organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890

2,4-Di­iodo­aniline

aSchool of Physical and Chemical Sciences, Queensland University of Technology, GPO Box 2434, Brisbane, Qld 4001, Australia
*Correspondence e-mail: g.smith@qut.edu.au

(Received 14 July 2009; accepted 31 July 2009; online 8 August 2009)

The structure of the title compound, C6H5I2N, shows a weak inter­molecular amine–amine N—H⋯N hydrogen-bonding inter­action, giving a helical chain which extends along the a axis. An intra­molecular N—H⋯I hydrogen bond is also observed.

Related literature

For related structures, see: Garden et al. (2002[Garden, S. J., Fontes, S. P., Wardell, J. L., Skakle, J. M. S., Low, J. N. & Glidewell, C. (2002). Acta Cryst. B58, 701-709.]). For the synthesis, see: Dains et al. (1935[Dains, F. B., Brewster, R. Q. & Davis, J. A. (1935). J. Am. Chem. Soc. 57, 2326-2327.]); Hodgson & Marsden (1937[Hodgson, H. H. & Marsden, E. (1937). J. Chem. Soc. pp. 1365-1366.]); O'Neil (2001[O'Neil, M. J. (2001). Editor. The Merck Index 13th ed., p. 560. Whitehouse Station, NJ, USA: Merck & Co.]). For graph-set analysis of hydrogen bonding, see: Etter et al. (1990[Etter, M. C., MacDonald, J. C. & Bernstein, J. (1990). Acta Cryst. B46, 256-262.]).

[Scheme 1]

Experimental

Crystal data
  • C6H5I2N

  • Mr = 344.91

  • Orthorhombic, P 21 21 21

  • a = 4.3870 (1) Å

  • b = 10.9626 (3) Å

  • c = 16.9778 (4) Å

  • V = 816.51 (3) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 7.62 mm−1

  • T = 200 K

  • 0.30 × 0.18 × 0.18 mm

Data collection
  • Oxford Diffraction Gemini-S Ultra CCD-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 1996[Sheldrick, G. M. (1996). SADABS, University of Göttingen, Germany.]) Tmin = 0.146, Tmax = 0.250

  • 6739 measured reflections

  • 1873 independent reflections

  • 1790 reflections with I > 2σ(I)

  • Rint = 0.024

Refinement
  • R[F2 > 2σ(F2)] = 0.018

  • wR(F2) = 0.038

  • S = 1.05

  • 1873 reflections

  • 90 parameters

  • H atoms treated by a mixture of independent and constrained refinement

  • Δρmax = 0.38 e Å−3

  • Δρmin = −0.47 e Å−3

  • Absolute structure: Flack (1983[Flack, H. D. (1983). Acta Cryst. A39, 876-881.]), 737 Friedel pairs

  • Flack parameter: −0.03 (4)

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N1—H11⋯I2 0.77 (3) 2.81 (3) 3.283 (4) 122 (3)
N1—H12⋯N1i 0.80 (4) 2.30 (4) 3.106 (5) 180 (5)
Symmetry code: (i) [x-{\script{1\over 2}}, -y+{\script{3\over 2}}, -z+2].

Data collection: CrysAlis CCD (Oxford Diffraction, 2008[Oxford Diffraction (2008). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, England.]); cell refinement: CrysAlis RED (Oxford Diffraction, 2008[Oxford Diffraction (2008). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, England.]); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]) within WinGX (Farrugia, 1999[Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837-838.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]) within WinGX (Farrugia, 1999[Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837-838.]); molecular graphics: PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]); software used to prepare material for publication: PLATON.

Supporting information


Comment top

Although the crystal structures of a number of nitro-substituted iodoanilines including 3-nitro-2,4-diodoaniline have been reported (Garden et al., 2002), that of the title compound 2,4-diiodoaniline C6H6I2N (I) has not been determined and the structure is reported here. The compound was isolated as the major crystalline product in the attempted synthesis of an adduct of 4,5-dichlorophthalic acid with 4-iodoaniline in aqueous ethanol. This conversion of 4-iodoaniline to 2,4-diiodoaniline has been reported previously (Dains et al., 1935), where solid 4-iodoaniline was observed to undergo a ca 25% conversion to the diiodo analogue in a sealed container over a period of three years. Hodgson & Marsden (1937) also reported the ready formation of the diiodo derivative along with 4-iodoaniline from the reaction of aniline with iodine.

In the structure of (I) (Fig. 1), single weak intermolecular hydrogen bonds are found [N1—H1···N1i, 3.106 (5) Å; symmetry code: (i) x - 1/2, -y + 3/2, -z + 2] [graph set S(4) (Etter et al., 1990)], linking the amine groups of 21 screw-related molecules. These form one-dimensional chains which extend down the a cell direction in the unit cell (Fig. 2).

In this structure there are, not unexpectedly, short intramoleculer N—H···I interactions [N1···I2, 3.283 (4) Å], which are also present in the structure of 2,4-diiodo-3-nitroaniline [3.254 (7) Å (Garden et al., 2002)]. However, unlike the nitro-derivative, no ππ stacking interactions are present in the structure of (I).

Related literature top

For related structures, see: Garden et al. (2002). For the synthesis, see: Dains et al. (1935); Hodgson & Marsden (1937); O'Neil (2001). For graph-set analysis of hydrogen bonding, see: Etter et al. (1990).

Experimental top

The title compound was formed in the attempted synthesis of a proton-transfer salt of 4,5-dichlorophthalic acid with 4-iodoaniline by heating together under reflux for 10 minutes 1 mmol quantities of the two reagents in 50 ml of 50% ethanol-water. After concentration to ca 30 ml, partial room temperature evaporation of the hot-filtered solution gave colourless needle prisms of 2,4-diiodoaniline [m.p. 368–389 K (O'Neil, 2001)] as the major product. This conversion of 4-iodoaniline to 2,4-diiodoaniline in the solid state has been reported previously (Dains et al., 1935).

Refinement top

The hydrogen atoms of the amino group were located in a difference Fourier map and their positional and isotropic displacement parameters were refined freely. Other H-atoms were included in the refinement in calculated positions [C—H = 0.93 Å) and treated using a riding model approximation, with Uiso(H) = 1.2Ueq(C).

Computing details top

Data collection: CrysAlis CCD (Oxford Diffraction, 2008); cell refinement: CrysAlis RED (Oxford Diffraction, 2008); data reduction: CrysAlis RED (Oxford Diffraction, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008) within WinGX (Farrugia, 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008) within WinGX (Farrugia, 1999); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: PLATON (Spek, 2009).

Figures top
[Figure 1] Fig. 1. Molecular configuration and atom naming scheme for (I). Displacement ellipsoids are drawn at the 50% probability level.
[Figure 2] Fig. 2. The one-dimensional hydrogen-bonded chain structure of (I) extending down the a axial direction of the unit cell, showing hydrogen-bonding associations as dashed lines. Non-interactive H atoms are omitted. [Symmetry code (i): x - 1/2, -y + 3/2, -z + 2].
2,4-Diiodoaniline top
Crystal data top
C6H5I2NDx = 2.806 Mg m3
Mr = 344.91Melting point = 368–369 K
Orthorhombic, P212121Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2abCell parameters from 5620 reflections
a = 4.3870 (1) Åθ = 3.0–32.2°
b = 10.9626 (3) ŵ = 7.62 mm1
c = 16.9778 (4) ÅT = 200 K
V = 816.51 (3) Å3Needle, colourless
Z = 40.30 × 0.18 × 0.18 mm
F(000) = 616
Data collection top
Oxford Diffraction Gemini-S Ultra CCD-detector
diffractometer
1873 independent reflections
Radiation source: Enhance (Mo) X-ray tube1790 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.024
ω scansθmax = 27.5°, θmin = 3.0°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
h = 55
Tmin = 0.146, Tmax = 0.250k = 1314
6739 measured reflectionsl = 2218
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.018H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.038 w = 1/[σ2(Fo2) + (0.0207P)2]
where P = (Fo2 + 2Fc2)/3
S = 1.05(Δ/σ)max = 0.003
1873 reflectionsΔρmax = 0.38 e Å3
90 parametersΔρmin = 0.47 e Å3
0 restraintsAbsolute structure: Flack (1983), 737 Friedel pairs
Primary atom site location: structure-invariant direct methodsAbsolute structure parameter: 0.03 (4)
Crystal data top
C6H5I2NV = 816.51 (3) Å3
Mr = 344.91Z = 4
Orthorhombic, P212121Mo Kα radiation
a = 4.3870 (1) ŵ = 7.62 mm1
b = 10.9626 (3) ÅT = 200 K
c = 16.9778 (4) Å0.30 × 0.18 × 0.18 mm
Data collection top
Oxford Diffraction Gemini-S Ultra CCD-detector
diffractometer
1873 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
1790 reflections with I > 2σ(I)
Tmin = 0.146, Tmax = 0.250Rint = 0.024
6739 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.018H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.038Δρmax = 0.38 e Å3
S = 1.05Δρmin = 0.47 e Å3
1873 reflectionsAbsolute structure: Flack (1983), 737 Friedel pairs
90 parametersAbsolute structure parameter: 0.03 (4)
0 restraints
Special details top

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
I20.57888 (5)0.42657 (2)1.08868 (1)0.0293 (1)
I40.48489 (5)0.28546 (2)0.75021 (1)0.0330 (1)
N10.1721 (9)0.6552 (3)1.0212 (2)0.0291 (11)
C10.2299 (7)0.5690 (3)0.9630 (2)0.0218 (9)
C20.4096 (8)0.4658 (3)0.97570 (19)0.0221 (9)
C30.4807 (8)0.3859 (3)0.9156 (2)0.0247 (9)
C40.3689 (8)0.4074 (3)0.8407 (2)0.0235 (10)
C50.1876 (8)0.5075 (3)0.8256 (2)0.0260 (11)
C60.1216 (9)0.5877 (3)0.8865 (2)0.0278 (11)
H30.602800.318200.925300.0300*
H50.110700.521000.775300.0310*
H60.001900.655800.876100.0330*
H110.190 (8)0.626 (3)1.062 (2)0.038 (9)*
H120.043 (8)0.704 (4)1.010 (2)0.040 (9)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
I20.0335 (1)0.0341 (1)0.0202 (1)0.0009 (1)0.0038 (1)0.0021 (1)
I40.0383 (1)0.0389 (1)0.0219 (1)0.0022 (1)0.0017 (1)0.0069 (1)
N10.037 (2)0.0222 (16)0.028 (2)0.0055 (15)0.0021 (16)0.0013 (15)
C10.0214 (15)0.0191 (16)0.0248 (18)0.0039 (15)0.0014 (14)0.0021 (14)
C20.0251 (16)0.0226 (16)0.0186 (17)0.0034 (15)0.0009 (14)0.0032 (11)
C30.0289 (18)0.0218 (14)0.0234 (17)0.0007 (11)0.0010 (16)0.0015 (12)
C40.0252 (17)0.0226 (18)0.0228 (18)0.0031 (13)0.0028 (14)0.0029 (13)
C50.027 (2)0.0313 (19)0.0197 (19)0.0028 (14)0.0018 (15)0.0044 (14)
C60.0323 (19)0.0236 (18)0.0276 (19)0.0028 (15)0.0007 (15)0.0051 (13)
Geometric parameters (Å, º) top
I2—C22.101 (3)C2—C31.381 (5)
I4—C42.099 (3)C3—C41.383 (5)
N1—C11.391 (5)C4—C51.379 (5)
N1—H120.80 (4)C5—C61.388 (5)
N1—H110.77 (3)C3—H30.9300
C1—C61.398 (5)C5—H50.9300
C1—C21.396 (5)C6—H60.9300
H11—N1—H12124 (4)I4—C4—C3118.6 (2)
C1—N1—H11110 (3)C3—C4—C5120.7 (3)
C1—N1—H12114 (3)C4—C5—C6119.1 (3)
N1—C1—C6119.9 (3)C1—C6—C5121.9 (3)
N1—C1—C2123.0 (3)C2—C3—H3120.00
C2—C1—C6117.0 (3)C4—C3—H3120.00
I2—C2—C1120.4 (2)C4—C5—H5120.00
I2—C2—C3117.7 (2)C6—C5—H5121.00
C1—C2—C3121.9 (3)C1—C6—H6119.00
C2—C3—C4119.4 (3)C5—C6—H6119.00
I4—C4—C5120.7 (2)
N1—C1—C2—I25.0 (5)C1—C2—C3—C40.7 (5)
N1—C1—C2—C3175.5 (3)C2—C3—C4—I4179.3 (3)
C6—C1—C2—I2178.9 (2)C2—C3—C4—C50.0 (5)
C6—C1—C2—C30.6 (5)I4—C4—C5—C6178.5 (3)
N1—C1—C6—C5176.5 (3)C3—C4—C5—C60.9 (5)
C2—C1—C6—C50.3 (5)C4—C5—C6—C11.0 (5)
I2—C2—C3—C4178.8 (3)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H11···I20.77 (3)2.81 (3)3.283 (4)122 (3)
N1—H12···N1i0.80 (4)2.30 (4)3.106 (5)180 (5)
Symmetry code: (i) x1/2, y+3/2, z+2.

Experimental details

Crystal data
Chemical formulaC6H5I2N
Mr344.91
Crystal system, space groupOrthorhombic, P212121
Temperature (K)200
a, b, c (Å)4.3870 (1), 10.9626 (3), 16.9778 (4)
V3)816.51 (3)
Z4
Radiation typeMo Kα
µ (mm1)7.62
Crystal size (mm)0.30 × 0.18 × 0.18
Data collection
DiffractometerOxford Diffraction Gemini-S Ultra CCD-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.146, 0.250
No. of measured, independent and
observed [I > 2σ(I)] reflections
6739, 1873, 1790
Rint0.024
(sin θ/λ)max1)0.649
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.018, 0.038, 1.05
No. of reflections1873
No. of parameters90
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.38, 0.47
Absolute structureFlack (1983), 737 Friedel pairs
Absolute structure parameter0.03 (4)

Computer programs: CrysAlis CCD (Oxford Diffraction, 2008), CrysAlis RED (Oxford Diffraction, 2008), SHELXS97 (Sheldrick, 2008) within WinGX (Farrugia, 1999), SHELXL97 (Sheldrick, 2008) within WinGX (Farrugia, 1999), PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H11···I20.77 (3)2.81 (3)3.283 (4)122 (3)
N1—H12···N1i0.80 (4)2.30 (4)3.106 (5)180 (5)
Symmetry code: (i) x1/2, y+3/2, z+2.
 

Acknowledgements

The authors acknowledge financial support from the Australian Research Council and the School of Physical and Chemical Sciences, Queensland University of Technology.

References

First citationDains, F. B., Brewster, R. Q. & Davis, J. A. (1935). J. Am. Chem. Soc. 57, 2326–2327.  CrossRef CAS Google Scholar
First citationEtter, M. C., MacDonald, J. C. & Bernstein, J. (1990). Acta Cryst. B46, 256–262.  CrossRef CAS Web of Science IUCr Journals Google Scholar
First citationFarrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838.  CrossRef CAS IUCr Journals Google Scholar
First citationFlack, H. D. (1983). Acta Cryst. A39, 876–881.  CrossRef CAS Web of Science IUCr Journals Google Scholar
First citationGarden, S. J., Fontes, S. P., Wardell, J. L., Skakle, J. M. S., Low, J. N. & Glidewell, C. (2002). Acta Cryst. B58, 701–709.  Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
First citationHodgson, H. H. & Marsden, E. (1937). J. Chem. Soc. pp. 1365–1366.  CrossRef Google Scholar
First citationO'Neil, M. J. (2001). Editor. The Merck Index 13th ed., p. 560. Whitehouse Station, NJ, USA: Merck & Co.  Google Scholar
First citationOxford Diffraction (2008). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, England.  Google Scholar
First citationSheldrick, G. M. (1996). SADABS, University of Göttingen, Germany.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSpek, A. L. (2009). Acta Cryst. D65, 148–155.  Web of Science CrossRef CAS IUCr Journals Google Scholar

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Follow Acta Cryst. E
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds